(1) Field of the Invention
The present invention relates to a projector device and, more particularly, to a projector device employing an auxiliary fitting or a lock mechanism for theft prevention.
(2) Description of Related Art
At present, such a lock mechanism as will be discussed hereinafter has been known as a theft prevention measure for a relatively portable, household electric appliance, such as a projector device, a note type personal computer and the like. Referring now to FIG. 7, there is illustrated a projector device 2 which is adapted to be locked by a lock mechanism 100. The lock mechanism 100 is called a kensington lock and serves as means to couple the projector device 2 to a stationary article such as a desk and the like, or another projector device, to thereby prevent the projector device 2 from being stolen. The lock mechanism 100 comprises a lock shaft 1a which is to be inserted through a laterally extending insertion slot 2a formed in an I/O case of a housing body of the projector device 2, and then engaged with the projector device 2, a body 1c supporting the lock shaft 1a and having a key hole formed therein, the body 1c being adapted to be operatively engaged with a separate key section 1b and then perform a locking operation, and a wire 1d connected at one end thereof to the body 1c and adapted to be coupled at the other end to the stationary article. The lock shaft 1a has a pair of projecting pieces 1a1 projecting radially from a tip end of the lock shaft 1a. After the lock shaft 1a of the lock mechanism 100 is inserted through the insertion slot 2a of the projector device 2, the key section 1b is operatively engaged with the key hole of the body 1c and then rotated through substantially 90 degrees. By this, the lock shaft 1a having the projecting pieces 1a1 is also rotated through substantially 90 degrees in an interior of the projector device 2. At this time, postures of the projecting pieces 1a1 of the lock shaft 1a become vertical relative to the laterally extending insertion slot 2a of the projector device 2, whereby the projecting pieces 1a1 are engaged with an inner surface of a wall of the projector device 2. Thus, the lock mechanism 100 is coupled to the projector device 2.
The above-mentioned lock mechanism is utilized for theft prevention purpose, so that a surface of the projector device 2 which surrounds the insertion slot 2a is required to have mechanical strength which is enough to prevent the lock mechanism 100 from being disengaged from the projector device, even if the lock mechanism 100 is pulled out or is pushed in with strong force, whereby the wall of the projector device 2 is broken. For this reason, the mechanical strength of the surface around the insertion slot 2a of the projector device 2 is added by a reinforcing bracket 3 which is shown in FIG. 8 and is to be mounted to a bracket fixing-section 2b1 (FIG. 8) provided on the I/O case of the projector device. Referring now to FIG. 8, the reinforcing bracket 3 comprises a reinforcing plate 3b for reinforcing the insertion slot 2a of the projector device, the reinforcing plate 3b having an insertion slot 3a substantially similar to the insertion slot 2a of the projector device 2, and a horizontal plate portion 3c so as to be substantially perpendicular to the reinforcing plate 3b. The mounting of the reinforcing bracket 3 to the bracket-fixing section is carried out in such a manner that the insertion slot of the reinforcing bracket 3 is aligned with the insertion slot 2a of the I/O case of the projector device 100. The lock shaft 1a of the lock mechanism 100 is inserted through the insertion slot 3a of the reinforcing bracket 3 and the insertion slot 2a of the projector device 2, and operatively engaged with the inner surface of the wall of the projector device 2 in the same manner as described above. By this, even if the lock mechanism 100 is pulled out and/or pushed in from outside the projector device 2, the reinforcing plate 3b can resist a pulling force and/or a pushing force which is applied to the projecting pieces 1a1 of the lock shaft 1a, so that breakage of the projector device 2 can be prevented. As discussed above, the I/O case of the projector device 2 has the bracket-fixing section 2b1 provided thereon for allowing the reinforcing bracket 3 to be fixed at a predetermined location.
FIG. 8 is a schematic perspective view of the bracket-fixing section 2b1 which is formed on the I/O case (not shown). The bracket-fixing section 2b1 comprises a pair of spaced apart guide portions 2b2, 2b3 for supporting both sides of the horizontal plate portion 3c of the reinforcing bracket 3, the guide portions 2b2, 2b3 being provided on the I/O case so as to stand up from the I/O case, and a boss 2b4 arranged between the guide portions 2b2, 2b3 so as to stand up from the I/O case and extending parallel to the general surface of the horizontal plate portion 3c of the reinforcing bracket 3 to be fixed to the bracket-fixing section 2b1. The guide portions 2b2, 2b3 have slits aligned with each other. A washer faced screw 5 is to be fastened to the boss 2b4. The fixing of the reinforcing bracket 3 to the bracket-fixing section 2b1 constructed as discussed above is carried out by first causing the horizontal plate portion 3c of the reinforcing bracket 3 to be inserted into the guide portions 2b2, 2b3 through the slits of the guide sections 2b2, 2b3 while causing the reinforcing plate 3b to be received in a space between the spaced apart guide portions 2b2, 2b3, whereby the reinforcing bracket 3 is positioned on the left and right sides. Then, the screw 5 is fastened into the boss 2b4, whereby vertical movement of the reinforcing bracket 3 is restricted by a region under a neck of the screw 5. In this way, the reinforcing bracket 3 is fixed to the bracket-fixing section 2b1 of the I/O case so as to be prevented from be laterally and vertically moved.
When the screw 5 is fastened into the boss 2b4 of the bracket-fixing section 2b1, the fastening of the screw 5 to the boss 2b4 of the bracket-fixing section 2b1 is required to be controlled at a predetermined torque. Generally, torque which will be produced in order to fasten the screw into the boss 2b4 is a torque of between 8 kN and 10 kN. Therefore, when a worker fastens the screw 5 into the boss 2b4, the worker performs a suitable torque control by utilizing a torque wrench. “The torque of the screw 5” is given to mean a torque which is produced when the screw 5 is fastened into the boss 2b4 until a region of the screw 5 which occupies a region under a head of the screw (a region under the neck of the screw) is abutted against an internally threaded peripheral portion of the boss 2b4. In this case, the I/O case is required to have a strength enough to resist the torque of the screw 5. The I/O case which is currently employed is made of resin and designed such that it has a thickness enough to withstand the torque.
However, it is desirable that the torque of the screw 5 for fixing the reinforcing bracket 3 to the bracket-fixing section 2b1 is more than 8 kN-10 kN, since the lock mechanism 100 is designed so as to be able to withstand the pulling force and/or pushing force which may be applied to the lock mechanism 100, and increase in the torque of the screw for fixing the reinforcing bracket 3 will make it possible to comply with a large pulling force and/or a large pushing force which may be applied to the lock mechanism. In addition, since the housing body of the projector device has an influence upon an impression of a visual appearance of the article, it is desirable that design freedom is provided to the housing body of the projector device. Concretely, it is desirable that there can be gained an increased degree of freedom in designing the article in such a manner that the housing body is made thin, to thereby make the weight of the entire article light and make the article easily to be carried, or in such a manner that cooling efficiency within the housing body is increased by forming a plurality of slits in the housing body. When the entire housing body is made thin, there is a possibility that the I/O case 2b will not withstand the fastening torque of the screw 5 and a torque of more than 8 kN-10 kN. Moreover, when the slits are formed in the housing body, the same drawback is presented.
A structure for mounting a top cover, which has been devised from the viewpoint of reduction in the number of components and reduction in assembly man-hours, is disclosed in Japanese Patent Application Laid-Open No. 2005-347437. More particularly, there is disclosed a structure for screw-fastening to a bottom chassis a top cover put on the bottom chassis, in which the top cover has recess surfaces provided on forward portions of left and right side walls thereof, insertion holes formed in the recess surfaces, through which screws are to be inserted, and engaging portions provided at rearward portions of the left and right side walls, the engaging portions being adapted to be engaged with the bottom chassis. Fixing of the top cover to the bottom chassis is carried out by causing the screws to be fastened into the insertion holes of the top cover put on the bottom chassis, and causing the engaging portions of the top cover to be engaged with the bottom chassis. This construction facilitates reduction in the number of screws for fixing the left and right side walls of the top cover to the bottom chassis, and reduction in assembly man-hours.
With the structure disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2005-347437, it is possible to reduce the number of the screws required to be used, but it is impossible to increase the fastening torque of the screw for fixing the reinforcing bracket in the projector device.